Court ruling may affect cell tracking by Chicago police

A secret cellular tracking system used by the Chicago Police Department could run afoul of a new U.S. Supreme Court ruling prohibiting authorities from searching cellphones without a warrant, experts said Wednesday.

The department has for several years been using cell site simulators — commonly known as IMSI catchers or Stingray devices — to scan cellphones for call logs, which include text messages. They also track phones’ locations, which the court didn’t address in this case. Though sources confirm the simulators’ use, the city has never publicly acknowledged having the equipment.

After Chicago police ignored a Freedom of Information Act request seeking information about the equipment’s cost, local activist Freddy Martinez sued the department this month to force the release of documents related to the simulators’ purchase. State law dictates that all expenditures of public funds are subject to open record laws.

“The fact they won’t disclose whether they even have the Stingrays suggests that they could be using it improperly,” said Matthew Topic, a transparency lawyer who is representing Martinez in his lawsuit.

A Chicago police spokesman declined to discuss how the Supreme Court ruling would affect department procedures or its use of simulators.

“Obviously, the ruling just came down (Wednesday) and our lawyers and department personnel are still evaluating how it might impact police operations,” spokesman Martin Maloney said.

In addition to federal agencies, police departments in at least 15 states have cell site simulators, according to the American Civil Liberties Union. The ACLU has been involved in several lawsuits aimed at releasing public documents connected to Stingray use.

Topic said he expects the Supreme Court ruling will prompt the city to rethink how it uses the simulators, especially because the systems have the ability to mine data from people who are near suspects but not the target of any law enforcement investigation.

“I would like to believe the Chicago Police Department doesn’t want to engage in wholesale Fourth Amendment violations,” he said. “I hope they would read the ruling and take a hard look at their procedures.”